NetScan for BL118 PEANUT Fermilab 22-23/Jan/2007

Possibility of non-bias analysis Naples already did full scanning for one brick. –Giovanni’s report Pilot analysis of BL118 NetScan is started. –5x5 25cm 2 area is scanned by SUTS Today I report first 21 plate data. We used base track for NetScan framework –For the first attempt. –How much we can reduce scanning power is next subject.

BL118 short history Exposure –Start : 2005/11/25 21:24:08(GMT) –End : 2006/02/25 23:02:59(GMT) 92days –Trig : (Beam stop period was there) ~250 events are expected. 2 times airplane flight –Nagoya ->Fermilab –Fermilab -> Nagoya -> develop

(57 in transportation)2(56 in transportation) Lead 3(55 in transportation) Lead 4(54 in transportation)55(3 in transportation) Lead 54(4 in transportation) Lead 53(5 in transportation) No flip Numbering on plate is 1 Beam direction Numbering on plate is 54 On upstream Brick structure

NetScan flow SUTS scanning for both side of film Base track reconstruction Align in transportation order –Reduce tracks reconstructed in transportation order from data set to clean up.(Virtual erasing) –For BL118, there is two transportation alignment. Align in exposure order –ECFSAL is used (Same as DONUT) –ECVTXA is used for vertex hunting.

SUTS scanning and base track Details are described in Morishima’s talk 5x5 25cm 2 is scanned –There was some mistakes in data taking –Fully overlapped 4x4cm 2 is used for quality check Base track is formed by SUTS standard software. –I’ve applied too tight base track selection for first trial 2 sigma Base track to micro track angular agreement was required for both X and Y for two emulsion layer. This means maximum tracking efficiency will be 83%. We wanted to see pure PH distribution for future analysis. So I did not cut by PH. (volume <= 2 is reduced)

Sample of base track selection This is plotting base tracks to micro track slope difference. But only plotting sum of PH larger than 25. –Minimum PH sum is 13 for this PL05. 2 sigma cut was applied for projected angular difference. –Since Plate 7, also detailed shrinkage error correction is done for selection. For this PL5, 416,733 out of 19,012,417 base track was selected

Virtual erasing Align in transportation order to reconstruct tracks while airplane flight. –We could find two transportation alignment as expected. Nagoya -> Fermilab –306,248 out of 4,779,566 for 21plates –Observed track density ~ 600/cm 2 Fermilab -> Nagoya –952,478 out of 4,779,566 for 21plates –Observed track density ~ 2,000/cm 2

Nagoya->Fermilab Fermilab->Nagoya Angular distribution

Nagoya->Fermilab Fermilab->Nagoya Pulse Height distribution

Nagoya->Fermilab Fermilab->Nagoya Efficiency as a function of slope

Nagoya->Fermilab Fermilab->Nagoya Efficiency as a function of plate

Nagoya->Fermilab Fermilab->Nagoya Overall resolution 8.5mrad10.7mrad10.9mrad14.3mrad Preliminary: Angle resolution is compared to angle obtained by position of first and last plate 4.7  m4.5  m 4.7  m

Alignment in exposure Virtual erasing is applied –3,530,479 base track remains for 21 plate. –Right table shows number of base tracks for each plate. –Still large amount of junk base track is there. ECFSAL –139,777 track (nseg>=2) are reconstructed. 128,015(2seg), 8,294 track (3seg) 3,468 track (nseg>=4) –Too large amount of nseg<=3 To reduce junk track, I applied 30mrad angular much for nseg<=3 tracks Reduced to 37,125(2seg), 1,475(3seg) f f f f f f f f f f f f f f f f f f f f f total

4 segment or more track

2 segment track3 segment track

Efficiency check ECFSAL reconstructed tracks nseg>=4 is used. –Fully overlapped scanning area 4x4 is used. –Start and end plate is not used for eff check. –Plate 1 and 21 eff. Can not check check

6.3mrad6.4mrad Note:angle is compared with angle obtained by position of start and end. 5.4  m6.0  m

Eff. As a function of slope Eff. As a function of plate

PH distributionTrack density

Preliminary vertex hunting ECVTXA is used for preliminary vertex hunting Another 23 two track vertex IP<20 is exist. Local alignment is not done.

Summary Apart from OPERA, NetScan is good method to perform non-bias neutrino interaction analysis. –Especially for electron neutrino location. NetScan with SUTS is feasible. –But, currently noise track density is bit too high to do clean analysis.SUTS scanning should be well tuned. –Also, cut applied for base track is too tight.Should be revised.

Outlook Before OPERA run, SUTS can be used for PEANUT analysis(half year) –While in this half year, number of SUTS will increase to 5. –At least, four bricks which exposed more than two month can be scanned by NetScan.(~1,000 neutrino interactions)